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arXiv · hep-th/9605094

An Explicit Large Versus Small Field Multiscale Cluster Expansion

A. Abdesselam·V. Rivasseau
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Abstract

We introduce a new type of cluster expansion which generalizes a previous formula of Brydges and Kennedy. The method is especially suited for performing a phase-space multiscale expansion in a just renormalizable theory, and allows the writing of explicit non-perturbative formulas for the Schwinger functions. The procedure is quite model independent, but for simplicity we chose the infrared $\ph^4_4$ model as a testing ground. We used also a large field versus small field expansion. The polymer amplitudes, corresponding to graphs without almost local two and for point functions, are shown to satisfy the polymer bound.

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A. Abdesselam, V. Rivasseau. 1996-05-14. An Explicit Large Versus Small Field Multiscale Cluster Expansion. https://doi.org/10.1142/s0129055x97000063

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